The selective reduction in PTPdelta expression in hepatomas.
The mRNA levels for receptor-like protein tyrosine phosphatases (PTPases), PTPalpha, PTPdelta, PTPgamma and LAR, were evaluated by Northern blot analysis in two types of chemically-induced rat primary hepatomas. In the four PTPases the PTPdelta mRNA was selectively reduced in these hepatoma tissues. It was also diminished in HepG2 hepatoblastoma cell line and in all of the poorly differentiated ascites hepatoma cells examined. PTPalpha, PTPgamma and LAR did not show such a characteristic decrease. This selective reduction in PTPdelta expression strongly suggests PTPdelta plays an important role in hepatocarcinogenesis, possibly as a tumor suppressor gene.
Urushibara
N
N
Section of Biochemistry, Institute of Immunological Science, Hokkaido University, Kita-15, Nishi-7, Kita-Ku, Sapporo 060, Japan.
Karasaki
H
H
Nakamura
K
K
Mizuno
Y
Y
Ogawa
K
K
Kikuchi
K
K
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D008099:Liver / Q000201:enzymology; D008113:Liver Neoplasms / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D008297:Male; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; C090899:PTPRD protein, human; D017027:Protein Tyrosine Phosphatases; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2